Ombuin is an O-methylated flavonol, a type of flavonoid.

Ombuin can be found in species of the genus Erythroxylum.

[1] Ombuin 3-sulfate can be isolated from Flaveria chlorifolia.

[2] Ombuin-3-rutinoside can be isolated from Phytolacca dioica, the ombu tree.

[3] Ombuin-3-O-rhamnosylglucoside can be found in Erythroxylum rufum.